when used 'correctly'.
All my auctions have links to my store and 'about me' page. There you will find 'ebay legal' links to my website.
My customised ebay 'item won email' also contains the links + more detail. Many of my website customers found me through ebay.
I treat ebay fees as 'marketing costs'

I keep track of some brief statistics which you may find interesting.

In two years of chip selling on ebay I have sold approx 9000 chips to 2500 buyers.
In one year of the website I have sold approx 20,000 chips to 1000 buyers. About 800 of those bought from me through ebay first and many found the website through the links above.
I have up to 91 new issue customers (depending on what the new issues are) - 50% of these found me via ebay.
I have about 100 further customers (many from this board) who generally buy via email only.
On days I have ebay auctions running I usually get between 150 and 300 website hits through the links. Thats about 1c per clickthru - approx 20 times cheaper than Google adwords for example.
I also get about the same number of clicks via this board (150 a day)